Plan for "Over the River" by Christo. (By Andre Grossman Cristo 2010)

Though permits are still pending, the Bureau of Land Management will allow the $50 million project, which will be funded by the artist, to go forward, after it determined it will not have any negative impact on the environment. “Over The River” is estimated to generate $121 million in economic output and draw 400,000 visitors during construction and display, according to the agency.

In the years that the proposal has been pending, environmentalists have fought fiercely against a work of art that they say will forever alter an animal habitat, and will make life difficult for those who live in the area as the art is constructed and displayed. As proposals to mitigate the project’s harm were developed, the environmentalists even found themselves at odds with each other.

“I am so angry,” Carol Neville, an area fly fishing guide told the LA Times last year. “People think we're a bunch of Podunk hicks who don't appreciate ‘art.’ This is about my life. This is my home. Who is going to be the resident guardians of the environment if not people like me?”

The Sierra Club said in a statement that it is adopting a “no position” stance on “Over the River,” angering some members. The Sierra Club reviewed the environmental impact statement for the project and determined that no adverse or beneficial environmental impacts will come of the project, so it has no reason to support or oppose it.

Christo, who originally envisioned the project with his late wife, Jeanne-Claude, took pains to ensure that the design of his project does not harm wildlife or vegetation. However, opposition groups such as “Rags Over the Arkansas River” say that any project, no matter how temporary, will cause environmental harm from the influx of tourists that will come to the area.

Jeanne-Claude and Christo have created environmental art installations all over the world, from draping New York’s Central Park for “The Gates,” to swathing islands in Miami’s Biscayne Bay with pink cloth. The National Gallery of Art announced Tuesday that Christo had donated two preparatory collages of “Over the River” to the museum. An exhibition of their plans for “Over the River” was on display at Washington’s Phillips Collection in 2008. Reviewing the show, Blake Gopnik wrote:

The piece may end up looking great, and changing the way we think of nature and the works of man. (One of Christo's first great projects, the "Running Fence" that stretched across 24 miles of California hills in 1976, seemed to do just that.) Or, as an example of 1970s art held over to the 21st century, "Over the River" may turn out to be a vast waste of time, money and resources. There's no way to know unless, or until, the thing gets built.

After all, the whole point of this kind of art is to make work that's so big, so ambitious and so full of impact that only nature can contain it. It's about escaping white-walled galleries, not filling them.

Drawings of the "Over the River" project are pictured in the background as Christo and Jeanne-Claude arrive for a news conference at a gallery displaying their work in Denver in 2008. (Ed Andrieski/AP)